Comparative molecular field analysis of fenoterol derivatives interacting with an agonist-stabilized form of the β2-adrenergic receptor
摘要:
The beta(2)-adrenergic receptor (beta(2)-AR) agonist [H-3]-(R,R')-methoxyfenoterol was employed as the marker ligand in displacement studies measuring the binding affinities (K-i values) of the stereoisomers of a series of 4'-methoxyfenoterol analogs in which the length of the alkyl substituent at alpha' position was varied from 0 to 3 carbon atoms. The binding affinities of the compounds were additionally determined using the inverse agonist [H-3]-CGP-12177 as the marker ligand and the ability of the compounds to stimulate cAMP accumulation, measured as EC50 values, were determined in HEK293 cells expressing the beta(2)-AR. The data indicate that the highest binding affinities and functional activities were produced by methyl and ethyl substituents at the alpha' position. The results also indicate that the K-i values obtained using [H-3]-(R,R')methoxyfenoterol as the marker ligand modeled the EC50 values obtained from cAMP stimulation better than the data obtained using [H-3]-CGP-12177 as the marker ligand. The data from this study was combined with data from previous studies and processed using the Comparative Molecular Field Analysis approach to produce a CoMFA model reflecting the binding to the beta(2)-AR conformation probed by [H-3]-(R,R')-4'-methoxyfenoterol. The CoMFA model of the agonist-stabilized beta(2)-AR suggests that the binding of the fenoterol analogs to an agonist-stabilized conformation of the beta(2)-AR is governed to a greater extend by steric effects than binding to the [H-3]-CGP-12177-stabilized conformation(s) in which electrostatic interactions play a more predominate role. (C) 2013 Elsevier Ltd. All rights reserved.
Synthesis of boronic acid derivatives of tyropeptin: Proteasome inhibitors
摘要:
Boronic acid derivatives of tyropeptin were synthesized with TP-110 as the lead compound. Due to the lability of the aminoboronic acid moiety, careful design of the deprotection and coupling sequence was required. Liquid-liquid partition chromatography was found to be a powerful tool for purification of compounds of this class. The obtained derivatives showed potent inhibitory activities against the human 20S proteasome in vitro. (C) 2009 Elsevier Ltd. All rights reserved.
The beta(2)-adrenergic receptor (beta(2)-AR) agonist [H-3]-(R,R')-methoxyfenoterol was employed as the marker ligand in displacement studies measuring the binding affinities (K-i values) of the stereoisomers of a series of 4'-methoxyfenoterol analogs in which the length of the alkyl substituent at alpha' position was varied from 0 to 3 carbon atoms. The binding affinities of the compounds were additionally determined using the inverse agonist [H-3]-CGP-12177 as the marker ligand and the ability of the compounds to stimulate cAMP accumulation, measured as EC50 values, were determined in HEK293 cells expressing the beta(2)-AR. The data indicate that the highest binding affinities and functional activities were produced by methyl and ethyl substituents at the alpha' position. The results also indicate that the K-i values obtained using [H-3]-(R,R')methoxyfenoterol as the marker ligand modeled the EC50 values obtained from cAMP stimulation better than the data obtained using [H-3]-CGP-12177 as the marker ligand. The data from this study was combined with data from previous studies and processed using the Comparative Molecular Field Analysis approach to produce a CoMFA model reflecting the binding to the beta(2)-AR conformation probed by [H-3]-(R,R')-4'-methoxyfenoterol. The CoMFA model of the agonist-stabilized beta(2)-AR suggests that the binding of the fenoterol analogs to an agonist-stabilized conformation of the beta(2)-AR is governed to a greater extend by steric effects than binding to the [H-3]-CGP-12177-stabilized conformation(s) in which electrostatic interactions play a more predominate role. (C) 2013 Elsevier Ltd. All rights reserved.
Synthesis of boronic acid derivatives of tyropeptin: Proteasome inhibitors
Boronic acid derivatives of tyropeptin were synthesized with TP-110 as the lead compound. Due to the lability of the aminoboronic acid moiety, careful design of the deprotection and coupling sequence was required. Liquid-liquid partition chromatography was found to be a powerful tool for purification of compounds of this class. The obtained derivatives showed potent inhibitory activities against the human 20S proteasome in vitro. (C) 2009 Elsevier Ltd. All rights reserved.